Abstract

The federal system in Germany has created a segmented library landscape. Instead of a central entity responsible for cataloguing and indexing, regional library unions share the workload cooperatively among their members. One result of this approach is limited sharing of cataloguing and indexing information across union catalogues as well as heterogeneous indexing of items with almost equivalent content: different editions of the same work. In this paper, a method for clustering entries in library catalogues is proposed that can be used to reduce this heterogeneity as well as share indexing information across catalogue boundaries. In two experiments, the method is applied to several union catalogues and the results show that a surprisingly large number of previously not indexed entries can be enriched with indexing information. The quality of the indexing has been positively evaluated by human professionals and the results have already been imported into the production catalogues of two library unions.